Mercapto functional groups are useful in polymer cross-linking. They can be readily crosslinked using an oxidizing agent or via a free radical reaction to form a disulfide linkage. The disulfide linkage can be reversibly cleaved, for example, by using a reducing agent. Such a reversible crosslinking property has been used to synthesize a wide variety of bioresorbable polymers including hydrogels.
In this regard, mercapto succinic acid and its derivative should offer an attractive way to prepare a wide variety of polymers with sulfur pendant groups for further crosslinking, for example, in bioresorbable and hydrogel materials. They also may find use in applications such as “permanent” type hair treatments or as metal scavengers (say in resolving cadmium or other heavy metal poisoning or in removing cadmium or other heavy metal pollutants from a waste stream or other source).
Accordingly, there is a need for mercapto succinic acids and derivatives that are useful in polymerization.